You should calculate your total crit-chance on HotA, (Max fury, buffs) to see where that leaves you. If you find yourself above 100% crit you "could" consider going Fire%/STR/CHD. D3planner is great for most of that as you can see your build with all 3 Hellfire options and choose for yourself.

Being 100% under Wrath of the Berserker is a great toughness boost. More crit = more blood funnel procs, more attack speed = more procs, 20% dodge is huge, and 20% movespeed allows you to avoid affixes with more ease.

I got stuck at around Grift 50 (crap gear) up until i could have WotB 100% of the time. Which you can get with 47% CDR and Boon (someone correct me if i'm wrong)

You are going to climb if you really are better than the players you are matched with, if you influence one win out of 10 then you will climb.

I had the same issue, my skill bonus worked up until rank 3, then i started duoing with a friend new to the game (but decent, just less awarness etc.) and being a duo we got matched with higher players and went on a crazy lose streak which brought me down to rank 10. I've been solo'ing since then, and managed to bring myself back to 50-50 at rank 7-8. Altough I don't know if by going over that 50-50 i will be able to get the skill bonus again :/

I speak both fluently, it's just that it is easier for me to type in english. Thank you for the advice, and i've already started contacting people to see if I could maybe stay for a month and look from there.